the present study has been done with the purpose of identifying the amount of success of performing lesson study in girl’s exceptional elementary school. Research method was Causal-Comparative and the statistical community were included (N=76) all exceptional students girl students in Hamedan city.Using random sampling about 14 students were selected as study sample. The data gathering instrument was researcher made questionnaire .The instrument validity reported as acceptable by experts and its reliability using cronbach alpha coefficient computed equal to0/896. The collected data were analyzed using descriptive static indices including mean, standard deviation and independent t-test. Findings showed that lesson-study has increased the success of exceptional students.